The invention relates to ultrasonic inspection and, more particularly, to apparatus and methods for simultaneously receiving data from a plurality of ultrasonic transducers.
Ultrasonic inspection is widely used in the manufacture of components for aircraft and other industrial equipment. In many applications, every portion of a part must be examined. Therefore, ultrasonic inspection systems typically employ a large number of transducers in order to keep the inspection time per unit at an acceptable value. For certain types of components, arrays of transducers are employed in a mode known as Through Transmission Ultrasonic (TTU) inspection in which a first array of transducers is disposed on one side of a work piece to transmit ultrasonic energy and a second array of ultrasonic transducers is disposed on the opposite side of the workpiece to receive the ultrasonic energy transmitted through the workpiece.
For materials exhibiting a high ultrasonic attenuation, such as honeycomb material, it is necessary to apply large amounts of ultrasonic energy to the workpiece in order to obtain the required signal-to-noise ratio at the receiving end. One method of providing such large amounts of transmitted ultrasonic energy is to simultaenously energize two or more ultrasonic transmitting transducers. Data from a corresponding number of receiving transducers may be simultaneously received and analyzed to detect the presence of defects. For example, for certain types of honeycomb material, it has been determined that the simultaneous energization of four ultrasonic transducers can provide the requisite amount of energy input to the workpiece. Other types of workpieces may be most advantageously inspected using the simultaneous energization of other numbers of transmitting transducers, for example, two or three.
In such situations, it is usually desirable to simultaneously receive data from a corresponding number of receiving transducers. For other applications, however, it has been determined that defects may be more readily detected when data is analyzed by simultaneously receiving from a differing number of receiving transducers. However, in prior art ultrasonic defect detection systems, it was difficult or impossible to readily change the number of ultrasonic receiving transducers from which data was simultaneously received. It is therefore an object of the present invention to provide an apparatus and methods for ultrasonic detection of defects having a high inspection rate and in which the number of transducers from which data is simultaneously received can be easily and conveniently altered. It is a further object of the invention to provide such capability at the lowest possible cost.